OLIVER WENDELL HOLMES was born in Cambridge, Massachusetts, August 29, 1809, and educated at Phillips Academy, Andover, and Harvard College. After graduation, he entered the Law School, but soon gave up law for medicine. He studied first in Boston, and later spent two years in medical schools in Europe, mainly in Paris. On his return he began to practise in Boston, but in two years he was appointed professor of anatomy at Dartmouth College, a position which he held from 1838 to 1840, when he again took up his Boston practice. It was soon after this, in 1843, that he published his essay on the Contagiousness of Puerperal Fever, his only contribution of high distinction to medical science. From 1847 to 1882 he was Parkman professor of anatomy and physiology in the Harvard Medical School. He died in Boston, October 7, 1894.

In spite of the importance of the paper here printed, Holmess reputation as a scientist was overshadowed by that won by him as a wit and a man of letters. When he was only twenty-one his Old Ironsides brought him into notice; and through his poetry and fiction, and the sparkling talk of the Breakfast Table series, he took a high place among the most distinguished group of writers that America has yet produced.